Various curable and foamable phosphazene polymers have been disclosed in the prior art. For example, U.S. Pat. No. 4,076,658 describes the preparation of poly(aryloxyphosphazene) copolymers and foams prepared therefrom. Because these copolymers are solid at ambient temperatures (i.e. 23.degree. C.-27.degree. C.), elevated temperatures are required in the fabrication of products therefrom, e.g. in the fabrication of foams. In an exemplary foaming procedure the milled, foamable mixture was precured for ten minutes at 230.degree. F. under 2000 psi and then free expanded in a circulating air oven for 30 minutes at 300.degree. F.
Because much energy is consumed in such conventional operations, a procedure for foaming and/or curing of substituted polyphosphazenes without large energy and investment requirements would be a welcomed contribution to the art.